JP2011513035A - Syringe safety device - Google Patents

Abstract

  A safety member (80) for use with the injection device (12) is disclosed. The safety member has a blocking ring that extends into the housing (14) of the injection device in a blocking relationship with respect to the latch member (55) associated with the trigger mechanism (64) of the syringe, Block movement of a portion of the trigger mechanism to the firing position. The safety member further has a manipulable portion (82, 64) disposed on the outside of the housing to release the block for the user to remove the safety member from the housing and allow the firing mechanism to fire the syringe. Configured to be manually operated.

Description

  The present invention relates to a syringe with a safety device, and more particularly to a syringe with a device that helps to prevent inadvertent firing.

  There are various injection devices that use some form of automatic mechanism to actuate the injection of liquid medication to the patient. Examples of such devices include both needleless and needle-assisted jet injectors and automatic injectors. The exact mechanism used to complete the injection may vary within and between these devices, but most are within the injection mechanism and the motion used to drive the injection mechanism during use. It has a function to store energy. In addition, many known injection mechanisms have a trigger mechanism that secures the device so that kinetic energy remains stored until an injection is desired, thereby releasing and storing the injection mechanism upon actuation of the trigger. The kinetic energy that has been driven can drive the injection mechanism resulting in an injection.

  Examples of needleless jet injectors are described in US Pat. Nos. 5,599,302, 5,062,830 and 4,790,824. These conventional syringes administer the drug as a fine, high-speed jet that is delivered under sufficient pressure to allow the jet to penetrate the skin. The pressure used to deliver the drug typically exceeds approximately 27.58 MPa (approximately 4000 psi) inside the compartment containing the drug in the syringe. The injection mechanism of such a needleless jet injector can be arranged to apply a force to the drug storage chamber in the device so as to provide the required pressure therein.

  Self-injectors or auto-injectors such as those disclosed in US Pat. Nos. 4,553,962 and 4,378,015 and WO 95/29720 and 97/14455 are manual subcutaneous It is configured to inject the drug at the same rate and in the same manner as the syringe. The self-injector or auto-injector has a needle that extends to penetrate the user's skin when activated and delivers the drug by movement of the drug container and associated needle. Thus, the mechanism that provides the force to deliver the drug in the auto-injector and the auto-injector also extends the needle and drug container so that the needle is inserted into the user's skin, and thereafter It is also used to force the drug to be released from the container through the needle by applying a force to a plunger movably disposed within the container. Thus, for example, an automatic syringe from Owen Mumford uses a very low pressure to inject the drug, which is injected at a relatively slow flow through the needle. The pressure applied to the drug chamber of this type of device is very low, up to about 413.7 kPa (about 60 psi) and takes about 5-10 seconds to inject 1 mL.

  In addition, needle assisted jet injectors have been developed that utilize needles to penetrate the skin first, most often to a shallower depth than with conventional hypodermic or automatic injectors. As the needle penetrates the skin, the jet mechanism is activated and the liquid containing the drug in the syringe is pressurized and released through the needle and into the skin. The injection mechanism of the needle assisted jet injector is configured to move the drug container and needle forward to penetrate the skin and then apply the necessary injection force to a plunger movably disposed within the container. be able to. Alternatively, the needle and drug container are properly positioned to penetrate the skin by being in close proximity to the skin so that the needle can be inserted while the needle and drug container remain in a fixed position, and injection The mechanism can be configured to pressurize the container. The pressure of the drug in the syringe can be lower than that of a conventional jet injector because the strong outer layer of skin has already been pierced by the needle. Similarly, the pressure of the drug is preferably higher than in an auto-injector, etc., so that the drug is substantially left in the body by needle penetration and penetration into the skin or tissue under the skin. It penetrates to a sufficient depth. A further benefit of higher pressure is that the time of injection is shortened, thereby reducing psychological trauma to the patient and the user inadvertently removing the syringe from the injection site. In addition, the possibility of ending early is reduced.

  The kinetic energy associated with the trigger and injection mechanisms is stored, resulting in accidental firing due to sudden movement during shipment or mishandling of the device by the user, including accidental actuation of the trigger mechanism there's a possibility that. Due to accidental firing of the injection mechanism, depending on the type of injection device, the drug can be released from the device, which can be dangerously high pressure. Furthermore, accidental firing can cause the needle to move forward relative to the device with sufficient force to penetrate the skin.

What is needed is a syringe that reduces the risk of accidental firing during shipping or handling.
Furthermore, many such injection devices are intended to be used only once. Accordingly, a locking mechanism is desired that prevents it from being repeatedly used unintentionally.

  The present invention relates to a syringe. The syringe has a housing and a container portion disposed within the housing. The container defines a fluid chamber that contains the drug, and a plunger that defines a portion of the fluid chamber is movably disposed therein. The syringe also includes a firing mechanism having a ram attached to the plunger and extending axially therefrom, and a latch movably disposed within the housing and configured to engage a portion of the ram. Have. The syringe is movably disposed within the housing between a ready position where the latch is held engaged with a portion of the ram and a firing position where the latch is released to allow movement of the ram. It further has a trigger. A safety member can be disposed relative to the housing to limit movement of the trigger to the firing position.

  In one embodiment, an opening may be formed in the housing and the safety member may have a blocking member having an end disposed within the housing to abut a portion of the trigger. In such an embodiment, the blocking member extends through the opening in the housing and is attached to the body portion of the safety member located outside the housing.

  In another embodiment, the syringe can further include a protector extending distally of the housing, which is retractable from the protected position to the activated position with respect to the housing. Retraction to the operating position allows a part of the protective equipment to move the trigger to the firing position. In such embodiments, the safety member can limit movement of the trigger mechanism to the firing position by preventing movement of the protector to the activated position. The safety member can have a blocking member and a body portion, the blocking member having an end disposed within the housing to abut a portion of the protector. The blocking member can extend through the opening of the housing and be coupled to the body portion, and the body portion is preferably disposed outside the housing. Additionally or alternatively, the syringe can have a sleeve mounted in the housing and configured to hold the container so that the safety member is movable from the first position to the second position. And a locking element slidably associated with the sleeve. In such embodiments, the first position is such that the protector can be retracted into the actuated position, and the second position is such that the locking element is disposed in a fixed relationship with the sleeve and is protected. This is the position that prevents the tool from moving to the operating position. A further additional or alternative safety member can be in the form of a cap configured to cover and surround the open end or protector. The protector can have a flange, and the cap can have a protrusion, whereby a snap fit is achieved between the protector and the cap so that a portion of the cap abuts a portion of the housing, which The cap limits the retracting of the protective device into the operating position.

  These and other objects, features and advantages of the present invention will become apparent from a consideration of the following non-limiting detailed description considered in conjunction with the drawings.

It is a side view of the injection apparatus by embodiment of this invention. 2 is a cross-sectional view of the injection device of FIG. 1 in a safe state, taken along line AA. FIG. FIG. 3 is an enlarged view of a part of the cross section shown in FIG. 2. It is a perspective view of the safety member used in connection with the injection device of FIG. It is a perspective view of the safety member used in connection with the injection device of FIG. FIG. 6 is a perspective view of an alternative safety member. FIG. 2 is a further cross-sectional view of the device of FIG. 1 in a safe state. FIG. 2 is a cross-sectional view of the injection device of FIG. 1 in a ready state. It is sectional drawing of the injection apparatus of FIG. 1 at the time of the start of an injection state. It is sectional drawing of the injection apparatus of FIG. 1 at the time of completion | finish of an injection state. FIG. 2 is a cross-sectional view of the injection device of FIG. 1 in a locked state. FIG. 6 is a perspective view of an injection device according to a further alternative embodiment of the present invention. It is sectional drawing of the injection apparatus of FIG. FIG. 6 is a perspective view of an injection device according to a further alternative embodiment of the present invention. It is sectional drawing of the injection apparatus of FIG. FIG. 2 is an exploded view of a portion of a trigger mechanism associated with the injection device of FIG. FIG. 2 is a perspective view of a needle protector according to the embodiment of the syringe of FIG. It is sectional drawing of the cap shown in FIG. 2 is a graph showing the pressure in the liquid chamber of a preferred injection device as a function of time.

  With reference to FIGS. 1 and 2, a preferred embodiment of the syringe 12 has an outer housing 14 configured to allow a user to handle the syringe 12. The outer housing 14 substantially houses most of the components shown in FIG. In an embodiment, the outer housing 14 is formed from two mating parts 14a, 14b that are attached to each other by snap-fitting or press-fit or using the adhesive, welding, etc. shown in FIG. Can be configured. The housing 14 has a fluid chamber 22 therein, which is configured to store and distribute liquid medication. In the embodiment shown in FIGS. 1 and 2, the fluid chamber 22 is formed in a pre-filled syringe 18 that fits within the housing 14, but is a known type of drug cartridge that may be pre-filled, refillable, etc. Other types of fluid chambers can be used, including Further, the fluid chamber 22 can be integrally formed in the housing 14. A safety member 80 is disposed at the proximal end of the outer housing 14a and is removably attached to the outer housing 14a by a plurality of tabs that extend through corresponding openings formed in the outer housing 14a. Thus, a press fit is formed between the safety member 80 and the outer housing 14a. In the context of this disclosure, the terms “proximal” and “distal” are used to refer to the position of the device relative to the user of the device when held to inject a liquid medicament into the patient. Thus, the location located proximal to the second location is closer to the user and vice versa. As described below, the safety member 80 is configured to prevent or reduce the possibility of unintentional firing of the injection device, for example during shipping or handling of the syringe 12. The safety member 80 may be removed by a syringe user to allow for virtually unlimited use of the syringe 12.

  In a preferred embodiment, the sleeve 16 is housed and mounted within the housing 12 and acts as a syringe support member. The sleeve 16 holds and positions a pre-filled syringe 18 of a type known in the art, such as a pre-filled syringe commercially available from Becton, Dickinson and Company under the name BD Hyperak ™. Composed. In a preferred embodiment, the sleeve 16 is substantially secured to the housing 14, such as by snap, adhesive, welding or another known fixture. The prefilled syringe 18 has a container portion 20 that defines a fluid chamber 22 within which is prefilled with the medicament to be injected. At the distal end of the prefilled syringe 18 is an injection assist needle 24. Needle 24 has an injection tip 26 configured to penetrate the patient's tissue, preferably the skin, as is known in the art. A needle lumen extends within the needle 24, as is known in the art. The lumen is in fluid communication with the drug in the fluid chamber 22 and is open at the needle tip 26 to inject the drug. Only the needle lumen of the needle 24 attached to the prefilled syringe 18 is the fluid communication means at the distal end of the fluid chamber 22.

  On the proximal side of the fluid chamber 22, on the opposite side from the needle 24 is a plunger 28 that seals the drug in the fluid chamber 22. Syringe wall 30 preferably comprises a tubular portion, which preferably has a needle 24 at the distal end and defines fluid chamber 22 by opening at the proximal end. Plunger 28 is slidably received in the tubular portion. The prefilled syringe 20 is configured such that when the plunger 28 is displaced in the distal direction, the volume of the fluid chamber 22 is reduced, thereby forcing the drug out of it and through the lumen of the needle 24.

At the distal end of the fluid chamber 22 is a needle hub portion 32 to which a needle is attached. A syringe flange 35 preferably extends radially from the proximal end of the syringe wall 30.
In a preferred embodiment, the syringe 18 has a syringe body 36 that includes a flange 35 and a wall 30, and the hub portion 32 is a unitary structure. The preferred material for the syringe body 36 is glass, although other materials can be used in other embodiments. A suitable prefilled syringe is BD Hyperak ™, which is available in various sizes and volumes, and can be prefilled with medication. The glass of the syringe body is bonded to the needle using an adhesive. Typical drugs and drug classes include epinephrine, atropine, sumatriptan, antibiotics, antidepressants, biologics and anticoagulants. The use of pre-filled syringes facilitates drug handling when assembling syringes, and dosage forms that can be injected with pre-filled syringes such as small volume parenteral containers are widely known.

  In order to radially position the distal end of the pre-filled syringe 18, the sleeve 16 preferably has a narrowed lumen portion 51 that is configured to abut the outside of the syringe wall 30. Is preferred. The sleeve 16 can be lined with an elastic material, such as an elastomer, or it can be integral with the rest of the sleeve 16, such as by a series of radially aligned elastically flexible fingers 53. Can be produced. The elastomer can be configured to abut the flange 34 of the syringe 18 at the proximal end of the sleeve 16.

  The firing mechanism is also preferably contained within the housing 12 and comprises a trigger 64 and a pair of elastically deformable latches 55. The firing mechanism also includes an inner housing 54 that can be attached to the outer housing 14, such as by snap, adhesive, welding or other known fittings. The latch 55 extends from the proximal end of the inner housing 54 and can be resiliently biased outward. Latch projections 56 project inwardly from the free end of the latch 55 and are received in each of the recesses 58 formed in the ram 60 in an inoperative relationship to the ram 60 so that prior to firing of the device. Prevent the ram 60 from moving distally. The ram 60 is biased toward the distal end of the syringe 12 by an energy source, preferably a compression spring 52, although other suitable energy sources such as elastomers or compressed gas springs or gas generators are alternative. Can be used as A preferred type of compression spring is a coil spring.

  A trigger 64 is provided on the outside of the inner housing to hold the latch 55 in the inward position, thereby maintaining the protrusion 56 in the recessed portion 58 in an actuating relationship and moving the ram 60 closer until firing is activated. Hold in place. The trigger 64 is preferably slidable axially relative to the latch 55 within the outer housing 14, and the trigger 64 preferably surrounds the latch 54. In the preferred embodiment, the trigger 64 is free to move relative to the outer housing 14 and relative to the outer housing, and the pressure applied by the latch 55 and the friction caused thereby after the safety member 80 is removed. Only in place. Preferably, nothing biases the trigger 64 away from the proximal end of the outer housing 14, including a spring or the like.

  The syringe 12 has a needle protector 66 that is movable relative to the outer housing 14. Needle protector 66 is shown in a protected position in FIGS. 2 and 7A where needle 24 is disposed within protector 66. When the needle protector is fully extended to the protected position, the ridge 65 shown in FIG. 13 abuts the inner surface of the outer housing 14 to maintain the needle protector 66 within the housing 14. The needle protector 66 is preferably retractable proximally with respect to the injection position within the outer housing 14, where the needle tip 26 and the needle 24 are positioned as shown in FIGS. 7B and 7C. The end is exposed to penetrate the patient. In a preferred embodiment, the proximal movement of the protective device is substantially prevented in the injection position.

  The needle protector 66 is associated with the trigger 64 so that when the protector 66 is displaced in the proximal direction, the trigger 64 also slides in the proximal direction to release the protrusion 56 from the recess 58. Preferably, the trigger 64 has a latching portion 68 (FIG. 6) that biases the projection 56 into position relative to the ram 60 in an inoperative relationship prior to firing of the device 12 and It contacts the latch 55 in such a relationship as to maintain. As the trigger slides proximally by retracting the protector 66 into the injection position, the latching portion 68 flexes the latch 55 inward so that it maintains the projection 56 within the recess 58 of the ram 60. Sliding over the portion of the latch 55 that makes contact, thereby allowing the projection 56 to move radially out of the recess 58 and thus out of relation to prevent actuation. When this occurs, the spring 62 biases the ram 60 relative to the plunger 28 and fires the jet injector.

  A cap 110 is preferably attachable to the distal end of the device 12 so as to cover the needle protector 66 and prevent its accidental displacement during handling prior to shipping or preparation for injection. The cap 110 can be attached to the distal end of the outer housing 14 by press fitting, screw fitting or the like. In the preferred embodiment, the cap 110 has a pair of inwardly extending protrusions 112, as shown in FIG. 14, which form a distally facing ridge 114. In such embodiments, the needle protector 66 is preferably formed to have a pair of radially extending flanges 67 that abut the distal ridge 114 of the protrusion 112 and cap 110. Is configured to be secured to the device 12. The upper edge 116 of the cap 110 preferably abuts the distal end of the outer housing 14, thereby holding the distal surface 14 of the protrusion 12 against the flange 67. This configuration of the cap 110 prevents the needle protector 66 from being compressed proximally into the housing when the cap 110 is juxtaposed between the protector 66 and the housing. Locking in the protective position helps prevent accidental firing of the injection mechanism.

  By twisting the cap 110 relative to the housing 14 so that the protrusion 112 does not move and align with the tab 67 (which allows the cap 110 to move distally from the needle protector 66). Can be removed from. To prevent the cap 110 from being accidentally removed from the device 12 by inadvertently twisting the cap 110, the cap snaps from its closed position before completing the rotation to remove the cap. It is preferred to engage the housing and / or protector so that it initially requires a strong force, such as needing to be released. For example, the upper edge 116 of the cap 110 is preferably inclined as shown in FIG. The tilt may include a curvature as shown, but generally the edge 116 should have one edge 118 higher than the outer edge 120. The distal end of the outer housing 14 preferably has a contour that matches the upper edge 16 of the cap 110. This configuration requires its deflection to allow the cap 110 to twist, and this configuration increases the force required to twist the cap 110 against the needle protector 66. In alternative embodiments, the cap may have a screw or cam relationship with the tab 67 or another relationship with the tab 67 so that the cap is removed by rotation.

  Cap 110 is preferably attached to device 12 during assembly of device 12. This can be done by properly aligning the cap 110 and twisting it against the needle protector 66 while applying a force directed proximally so that the protrusion 112 moves behind the flange 67. . Alternatively, the flange 67 can be configured to be deflectable inward by placing it on a corresponding tab 69 formed in the needle protector 66. In such embodiments, the cap 110 can be mounted on the needle protector 66 prior to incorporating the spring 72. This is because the spring 72 can prevent the inner deflection of the tab 96. Alternatively, the cap 110 can be elastically deformable so that the cap 110 can be pressed onto the needle protector 66 such that the protrusion 112 passes through the flange 67.

  The protector 66 is preferably resiliently biased in the distal direction towards the protected position by the compression coil spring 72. The needle protector 66 also has an axial opening 74 through which the needle 24 can be passed, which can be sized according to the type of syringe desired. With the configuration of this embodiment, the user pushes the distal end of the syringe 12 against the patient's skin and pushes the needle 24 into the skin at the insertion position at substantially the same speed as the syringe is pushed. Can do. When the needle 24 is fully inserted to the penetration depth at the insertion position, the trigger mechanism fires a jet injection to the injection site.

  In a preferred embodiment, such as for subcutaneous injection using a needle-assisted jet injector, the protector 66 is configured to allow needle insertion up to a skin penetration depth of up to about 5 mm below the skin surface. More preferably, the penetration depth is less than about 4 mm, and in one embodiment less than about 3 mm. Preferably, the insertion depth is at least about 0.5 mm, more preferably at least about 1 mm. In another embodiment, the distance 76 that the needle extends beyond the protective device 66 or the distal surface of the protective device 66 that contacts the skin is up to about 5 mm, more preferably up to about 4 mm, one embodiment Then, the maximum is about 3 mm. Preferably, the extension distance 76 is at least about 0.5 mm, more preferably at least about 1 mm, and most preferably at least about 2 mm. In a preferred embodiment, the tip 26 extends to a distance 76 of about 2.5 mm from the portion of the protector 66 that contacts the skin at the injection location.

  In another embodiment, such as for intramuscular injection using a needle assisted jet injector, the syringe is positioned at a distance of up to about 15 mm from the distal surface of the protector to the skin penetration depth in the patient, or alternatively from the distal surface of the protector. Up to be configured to be inserted. In one embodiment, this distance is between about 10 mm and 14 mm. Other exposed needle lengths can be selected for jet injections with different preferred penetration lengths of about 0.5 mm to about 20 mm to different depths under the skin. In these embodiments, the needle protector is configured to retract from a protective position, preferably covering the entire needle, to an injection position where the desired length of the end of the needle is exposed.

  As described above, the safety member 80 is removably attached to the distal end of the outer housing 14. Safety member 80 has a body portion 84 and a pair of elastically flexible legs 82 extending therefrom. In the illustrated embodiment, the legs 82 are configured to extend into corresponding holes or slots 15 (FIG. 4A) formed in the proximal face of the outer housing. The legs 82 are shaped to provide a press fit within the slot 15 to hold the safety member 80 on the housing 14. The legs 82 are preferably biased outwardly, and a tab 86 can be disposed on the outer surface thereof, which engages the inside of the outer housing 14 at the slot 15 to provide a safety member. Promotes retention of 80 on outer housing 14. The legs 82 are further preferably shaped such that the user can remove the safety member from the outer housing 14 when an injection is desired. However, the legs 82 should be such that the safety member 80 does not accidentally or unintentionally disengage from its attachment to the outer housing 14.

  The legs 82 are further configured to abut the proximal surface of the trigger 64, preferably the latching portion 68. The abutment of leg 82 against latching portion 68 preferably prevents or prevents proximal pushing or other movement of trigger 64 that fires the injection mechanism. In an embodiment, the safety member 80 can be removed from the outer housing 14 by forcing the protector 66 to move proximally so that the latching portion 64 causes the leg 82 to move proximally. Pressing, the legs 82 are pushed out of the slots in which they are received. However, the leg 82 is shipped or handled with the housing 14 and firing mechanism and the force required for the latching portion 68 to push the leg 82 out of the slot 15 is caused by vibration during shipping or by the fall of the device 12. It is preferably constructed in such a relationship that it is sufficient to prevent the trigger 64 from being pushed out of position from a sudden impact inside. More preferably, the safety member is configured such that, for example, a user of the device must apply a force of 453.6 g (1 lb) to 4.536 kg (10 lb) in order to remove the device from the outer housing 14. It is preferable. In a preferred embodiment, a force of about 1.13 kg (about 2.5 lb) to about 2.27 kg (about 5 lb) is required to remove the safety member 80 from the outer housing 14.

  FIG. 5 shows an alternative embodiment of the safety member 180. In this embodiment, the body portion 184 forms an elongated tab 188 that extends along the outside of the outer housing 14. The end of tab 188 includes a protrusion 189 configured to fit into a corresponding opening 187 formed in outer housing 14. In this embodiment, the interaction of the protrusion 189 and the corresponding opening 187 further secures the safety member 180 to the outer housing and further prevents the safety member 180 from being unintentionally detached from the housing 114b. The safety member 180 extends through its appropriately positioned corresponding opening 187 to a position where the elongate tab 188 is proximal to the protector 66 inside the outer housing 114 and distal to the trigger 64. It is preferably configured to be of an appropriate length to exist. Such an arrangement prevents movement of the protector 66 and prevents it from moving proximally and contacting the trigger 64 when an unintentional or accidental force is applied to the protector 64. .

  An alternative embodiment of the syringe 134 shown in FIGS. 8 and 9 includes a safety member 136 having an outer manipulable operating portion 138, a fastening member 140 and a blocking ring 142. The retaining ring 140 and the blocking ring 142 are preferably received in a safety opening 144 in the proximal portion of the housing 146 and extend radially from an operating portion 138 disposed outside the syringe housing 146.

  In the illustrated arrangement, the safety member 136 is in a safe position associated with the syringe 134 in a relationship where the blocking ring 142 prevents the trigger 148 from operating. In the safe position, the blocking ring 142 prevents accidental movement of the trigger 148 in the proximal axial direction. This movement results in the release of the latch protrusion 56 from the recess 58 of the ram 150, whereby the spring 152 biases the ram 150 and the injection is fired. The trigger 148 is preferably bell-shaped, thereby providing an additional proximal axial surface that abuts and is blocked by the blocking ring 142 in the blocking position.

  In this embodiment, if the safety member 136 is not in the safe position, the trigger 148 may accidentally slide proximally, such as by shock or vibration, thereby causing the syringe to fire unintentionally. . Also, if the safety member 136 is not in the safe position, accidental depression of the protective device 66 will cause the trigger 148 to move proximally and the syringe 134 to fire.

  The fastening member 140 preferably has a tip 154 that is enlarged or curved to provide a snap fit with the syringe housing 146 so that the safety member 136 is engaged with the syringe housing 146 in a safe position. This prevents or prevents the safety member 136 from accidentally disengaging from the safety opening 144. The preferred fastening member 140 is elastically flexible and allows it to be removed from the syringe housing 146 of the safety member 136 by grasping and pulling the operating portion 138 with the user's finger tip before intentionally firing the syringe 134. Flexible enough to allow for removal.

  Referring to FIGS. 10 and 11, the syringe 156 has a safety member 158 with a flexible body 160, which is preferably elastically flexible and is provided with a syringe housing 146. The outer side extends in the circumferential direction. The safety member 158 has a free tail 164 that is preferably angled from the housing 146 in the illustrated safe position, and the user's finger removes the tail 164 to separate and remove the safety member 158 from the syringe housing 146. Facilitates pushing up from the proximal side of the syringe 156.

  A blocking ring 162 of the safety member 158 is received in the safety opening 144. As described above, in the safe position, the blocking ring 162 is in a relationship that prevents its activation with the trigger 148, preventing the proximal axial movement of the trigger 148 and preventing inadvertent firing of the syringe. .

  The safety member described herein can be used with other types of syringes, including needle assisted jet injectors that do not employ pre-filled syringes, needleless syringes, and other types of motorized syringes. This safety mechanism is particularly effective because jet injectors have the power of injection when fired, even when fired inadvertently. The safety members 80, 136, 158 are preferably composed of a single piece, such as elastic plastic or metal, but other suitable configurations and materials can be used.

  In a preferred embodiment of the needle assisted jet injector, the spring 62 and the prefilled syringe 18 are configured to jet the drug. Thus, the spring 62 applies sufficient force to the plunger 28 to raise the pressure in the fluid chamber 22 to a level high enough to eject the drug from the needle 24 as a jet. Jet injection is understood as injection at a sufficient speed and force to disperse the drug farther away from the needle tip 26 and thus minimize back leakage at the injection site.

  The graph shown in FIG. 15 shows the pressure profile over time for a firing mechanism associated with an exemplary type of syringe that can use the safety devices disclosed herein. Although the pressure profile shown is of the type normally associated with jet injection, those skilled in the art will recognize that the various embodiments of the invention disclosed herein are not limited to jet injection, for example, accumulation. It will be appreciated that other types of injections that utilize the kinetic energy that has been used are also useful. Referring to the graph shown in FIG. 15, the numeral 288 represents the time when the preferred embodiment of the device 12 was fired and the numeral 290 represents the time when the drug injection is complete, preferably the plunger 28 is on the front wall of the container portion 220. Represents the time of collision. Number 292 represents the initial and peak pressure during injection and number 294 represents the final and low pressure during injection. Because the spring 62 of the preferred embodiment has a linear spring constant and penetrates the skin with an injection assist needle before initiating an injection, the pressure is substantially linear from the start of injection 288 until the injection is complete. To drop. The final pressure 294 at the end of the injection 290 is high enough so that the drug is still jet injected even at the end of the firing stroke of the ram 60, and the drug build-up on the bolus around the needle tip 26 There is very little or no.

  Preferably, the peak pressure during injection using the preferred needle assisted jet injector is less than about 6895 kPa (about 1000 psi), more preferably less than 3448 kPa (500 psi), and most preferably less than 2413 kPa (350 psi). At the end of the injection 80, the pressure 84 applied to the drug in the fluid chamber 22 is preferably about 551.6 kPa (about 80 psi), more preferably at least about 620.6 kPa (about 90 psi), most preferably at least About 689.5 kPa (about 100 psi). In one embodiment of the invention, the initial pressure 82 is about 330 psi and the final pressure is about 180 psi, whereas in another embodiment, the initial pressure 292 is about 300 psi. At the end of the injection 284, down to about 758.5 kPa (110 psi). Other injection rates are used for the other embodiments described herein. For example, needleless jet injectors can use injection pressures in the range of about 27.6 MPa (about 4,000 psi) or higher. Further, the auto-injector can use injection pressures in the range of about 60 psi or less. The needle used in the preferred embodiment is 26 gauge to 28 gauge, most preferably about 27 gauge, but alternatively when other components are configured in concert to provide the desired injection. Another other needle gauge can be used. Preferably, the components of the syringe 12 are configured to jet the drug into the underground injection site.

  The amount of drug contained in and injected from fluid chamber 22 is preferably about 0.02 mL to 4 mL, preferably less than about 3 mL, and in a preferred embodiment about 1 mL. Larger amounts can be selected depending on the particular drug and the dosage required. Preferably, the prefilled syringe is already assembled with the remaining parts of the jet injector 12 containing the required amount of medicament. In a preferred embodiment, the prefilled syringe contains about 1 mL of drug.

  A preferred injection rate is less than about 1.0 mL / sec, more preferably less than about 0.8 mL / sec, preferably at least about 0.4 mL / sec, more preferably at least about 0.5 mL / sec. And most preferably from about 0.60 mL / second to about 0.75 mL / second. Preferably, the full dose injection of the drug is completed in less than about 2 seconds, more preferably in less than about 1.5 seconds, and most preferably in less than about 1 second. Preferably, the drug injection takes at least about 0.5 seconds, more preferably at least 0.6 seconds. A preferred embodiment injects the drug at about 0.67 mL / sec and completes the 0.5 mL injection in about 0.75 sec. However, other injection rates are possible for alternative embodiments of the device 12 described herein.

  US Pat. No. 6,391,003 discloses several experimental results of pressure that can be applied to a drug in a glass cartridge using a 26 gauge needle and a 27 gauge needle. The following table shows exemplary injections at various peak pressures that can be used with glass prefilled syringes.

Pressure and time (in seconds) for 1 cc injection
Pressure 26 gauge needle 27 gauge needle 1034 kPa (150 psi) 2.1 4.2
1379 kPa (200 psi) 1.9 3.9
1655 kPa (240 psi) 1.7 3.3
2586 kPa (375 psi) 1.4 3.1
It is anticipated that higher pressures and flow rates will be used with shorter needle penetrations into the patient's skin to achieve jet injection to a specific desired depth substantially without back leakage of the drug . Alternative embodiments can use higher or lower injection pressures. For example, needleless syringes typically use higher pressures to penetrate the skin without a needle, and automatic injectors use lower pressures to simulate manual syringe injections.

  It has been found that by using the needle assisted jet injection of the preferred embodiment, a short needle can be used to inject drugs into various parts of the skin, preferably subcutaneously, with virtually no back leakage. . A needle extending about 2.5 mm from the needle protector 66, ie, a 27 gauge needle 24, with a flow rate of about 0.5 mL / sec, peak at about 2069 kPa (about 300 psi) and about 689.5 kPa (about 100 psi). By using the pressure in the fluid chamber 22 to finish, it was found that 1 mL of drug was successfully injected without back leakage close to 100% of the test injection. Thus, the needle assisted jet injector of the present invention allows for reliable jet injection of drugs using very short needles regardless of patient skin thickness or patient age, weight or other factors. .

  In a preferred embodiment, the device 12 has a locking element such as a locking ring 70 associated with the injection mechanism. As shown in FIGS. 7A-7D, the locking ring 70 is preferably disposed between the sleeve 16 and the needle protector 66 such that the needle protector 66 is attached to the outer housing 14 through a single injection cycle. It interacts with the sleeve 16 and the needle protector 66 so that it can move relative to it. This includes the movement from the protected position (FIG. 7A) to the injection position (FIGS. 7B, 7C) and the return to the protected position (FIG. 7D) due to the force of the compression spring 72 when the injection is complete. . When the needle protector 16 returns to the protected position at the end of the injection cycle, the locking ring is positioned relative to the sleeve 16 and needle protector 66 such that further movement therebetween is restricted.

  As shown in FIGS. 7A-7D, the needle protector 66 moves through one locking cycle, thereby moving the locking ring 70 relative to the sleeve 16 from the injection position to the locking position. In the injection position, the locking ring 70 is positioned such that its upper arm 71 engages a portion of the device associated with the drug chamber, such as a proximal notch 92 formed in the outer surface of the sleeve 16. The engagement of the upper arm 71 in the proximal notch 92 keeps the locking ring 70 releasable in the injection position. As shown in FIG. 12, the locking ring 70 may be generally annular in shape so as to surround the drug chamber, either directly or indirectly, such as by surrounding the sleeve 16. The locking ring 70 further includes a pair of lower arms 73 each having a tab 74 formed at the end thereof. When the locking ring is in the injection position, the tab 74 is received in a slot 95 formed in the needle protector 66 so that the needle protector can slide over the locking ring 70 a predetermined distance. As the needle protector 66 moves relative to the outer housing 14 to the injection position, the needle protector 66 moves over the locking ring 70 so that the tab 74 reaches the end of the slot 95 and is pushed inward. Sliding, so that the needle protector 66 can continue to move to the injection position. When the injection position is reached, the tabs 74 are aligned with the holes 96 in the needle protector 66 so that the lower arms 73 can return to their natural positions, where the upper surface of the tabs 74 is aligned with the edges of the holes 96. Engage and thereby lock ring 70 is coupled to needle protector 66.

  As the needle protector 66 returns to the protected position, it pulls the locking ring 70 distally, thereby releasing the upper arm 71 from the proximal notch 92. Preferably, the upper arm 71 and the proximal notch 92 are formed to have a mating ramp so that the ramp of the upper arm 71 extends into the proximal notch 92, etc. Engages another portion of the device associated with the drug chamber, but is forced outward by movement directed distally thereto. With this arrangement, the needle protector 66 moves the locking ring 70 together and out of the injection position as it moves distally over the sleeve 16 that remains fixed toward the protected position. be able to.

  When the needle protector 66 reaches the protected position, the upper arm 71 moves over the distal notch 93 formed in the sleeve 16, whereby the upper surface 75 of the upper arm 71 is moved to the distal notch 93. Engage with the upper surface 94. Further, in such a position, the flange 77 of the locking ring 70 abuts the surface 67 of the needle protector and prevents distal movement of the needle protector 66 relative to the locking ring 70. Due to this engagement, the locking ring does not move proximally with respect to the sleeve 16. Because the locking ring 72 is coupled to the needle protector 66 and the sleeve 16 is attached to the outer housing, the needle protector 66 is locked relative to the outer housing 14 and moves back to the injection position. It is prevented. This prevents the needle 24 from being accidentally exposed after use of the device 12.

  All references specifically identified in the detailed description section of this application are expressly incorporated herein by reference in their entirety. As used herein, the term “about” should generally be understood to refer to both the corresponding number and range of numbers. Moreover, all numerical ranges herein should be understood to include each whole integer within that range.

  While exemplary embodiments of the present invention have been disclosed herein, it will be appreciated by those skilled in the art that numerous modifications and other embodiments can be devised. For example, features for various embodiments can be used in other embodiments. In an alternative embodiment, the housing can be secured to the bracket, and an inner portion that defines at least the bottom of the chute can slide in and out of the housing. Accordingly, it will be understood that the appended claims are intended to cover all such modifications and embodiments that are within the spirit and scope of this invention.

Claims (13)

A housing;
A container portion disposed within the housing, defining a fluid chamber containing a drug, and including a plunger defining a portion of the fluid chamber, the plunger being movably disposed therein;
A firing mechanism having a ram attached to the plunger and extending axially therefrom;
A latch movably disposed within the housing and configured to engage a portion of the ram;
Within the housing, the latch is movable between a ready position where it is held engaged with the portion of the ram and a firing position where the latch is released to allow movement of the ram. Placed triggers, and
A safety member positionable relative to the housing to limit movement of the trigger to the firing position;
A syringe comprising:   The housing includes an opening formed in the housing, and the safety member includes a blocking member having an end portion disposed in the housing so as to contact a part of the trigger, and the blocking member includes The syringe of claim 1, extending through the opening in the housing and attached to a body portion of the safety member disposed outside the housing.   3. The blocking member is configured to be retained within the opening of the housing by a snap fit and removed by a user to allow movement of the trigger to the firing position. Syringe.   The trigger is movable from the ready position to the firing position by a first magnitude force, and there is a friction relationship between the trigger and the latch that provides a second magnitude holding force And the safety member provides a third magnitude of safety force to the trigger to limit movement of the trigger to the firing position, the first magnitude being the second magnitude. 3. The syringe of claim 2, wherein the syringe is about 1.13 kg (about 2.5 lbs) above it.   The latch has a flexible arm and a protrusion, the ram has a recess, the protrusion is receivable in the recess, and the trigger abuts the latch in the ready position; The syringe of claim 2, wherein a protrusion is retained in the recess.   The indentation and the projection are adapted so that the latch limits movement of the ram when the projection is held in the indentation by the trigger and by movement of the trigger to the firing position. The syringe of claim 5 configured to allow the recess to separate and allow the ram to move axially relative to the latch.   A protective device extending distally of the housing, wherein the protective device is retractable from a protected position to an operating position with respect to the housing; The part moves the trigger to the firing position, and the safety member limits the movement of the trigger mechanism to the firing position by preventing the protective device from moving to the operating position. A syringe as described in 1.   Further comprising a needle, the needle having a tip and associated with the chamber to penetrate the patient's skin for injecting the medicament, when the protector is in the protected position, Having a distal end disposed distal to the needle tip, and when the protector is in the retracted position, the distal end of the protector is disposed proximal to the needle tip. The syringe according to claim 7.   The housing has an opening, the safety member has a blocking member and a body portion, and the blocking member has an end portion disposed in the housing so as to contact a part of the protective device. The syringe of claim 7, wherein the blocking member extends through the opening of the housing and connects to the body portion, the body portion being disposed outside the housing.   The protector has a proximal end, the trigger has a distal end, and the proximal end of the protector is separated from the distal end of the trigger when the protector is in the protected position. The syringe of claim 9, wherein the syringe is disposed axially apart and the blocking member is disposed axially between the proximal end of the protector and the distal end of the trigger.   A sleeve mounted within the housing and configured to hold the container, wherein the safety member is slidable with the sleeve such that the safety member is movable from a first position to a second position; Having an associated locking element, wherein the first position is a position such that the protector can be retracted into the actuated position, and in the second position, the locking element comprises the sleeve and The syringe according to claim 7, which is arranged in a fixed relationship and prevents movement of the protective device to the operating position.   A spring disposed within the housing to resiliently bias the protector toward the protected position such that the protector returns to the protected position following retraction of the protector to the operating position; Further, the retracting of the protector causes the protector to engage with the locking member, and a subsequent return of the protector to the protected position causes the locking element to reach the second position. The syringe of claim 11 that moves.   The safety member is in the form of a cap configured to cover and surround the protective device with an open end or the protective device, the protective device having a flange, and the cap having a protrusion, Thereby, a snap fit is achieved between the protector and the cap, and a part of the cap abuts a part of the housing, whereby the cap retracts the protector into the operating position. 8. A syringe according to claim 7, wherein the syringe is limited.

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